This invention relates generally to gas-fired burner assemblies and, in particular, to gas-fired burner assemblies used in fireplaces.
For safety, ecology and ease of operation reasons, gasfired fireplace units are being increasingly used in new construction rather than traditional wood burning units. However, gas-fired fireplace units traditionally suffer from the problem that they do not generally have the same "look and feel" of a traditional wood-burning unit.
One attempt to overcome this problem was suggested by Pulone in U.S. Pat. No. 3,583,845. Pulone taught to place the burner pipe in an open-topped box having triangular sides that slope from the rear of the fireplace towards the front. A simulated log is positioned on a grate immediately above the box. The box is filled with sand. In operation, the gas percolates up through the sand and ignites at the surface of the sand. Such combustion gives the approximate appearance of a glowing bed of burning charcoal.
Unfortunately, Pulone and other prior art units are not wholly satisfactory. For example, the use of small grained noncombustible material in the burner pan, such as sand, frequently results in channeling of the gas as it percolates to the surface. Such channeling causes a marked non-uniformity in the ignition pattern across the surface of the sand. Also, the use of such small grain non-combustible materials inhibits the mixing of air with the gas, and sometimes results in the incomplete combustion of the gas.
In an attempt to get better air/gas mixing, large, irregularly-shaped granules such as crushed cinders have been tried. Although partially successful in this regard, the use of large, irregularly-shaped granules has not helped the gas distribution problem and has introduced the additional problem of excessive gas-flow noise.
Accordingly, there is a need for a gas-fired fireplace burner unit which more closely approximates the "look and feel" of a traditional wood burning unit.
Along these lines, there is a need for a gas-fired fireplace burner unit wherein gas is evenly distributed across the surface of the non-combustible material.
Finally, there is a need for a gas-fired fireplace unit wherein the gas is wholly aerated to assure complete combustion, without a resulting excessive amount of gas-flow noise.